Conduit for interventional procedures

ABSTRACT

A conduit, such as an introducer sheath, catheter, or guide catheter, incorporating two or more separate lumens to prevent the entanglement of guidewires located at least partially within the conduit. The lumens are separated by at least one disruptable barrier that allows multiple lumens to be converted into fewer lumens prior to or as a device is advanced through the introducer sheath.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Novel conduits, such as guide catheters and catheter introducer sheaths,for use in interventional procedures, particularly introducer sheathsadapted for use with multiple guidewires.

2. Description of Related Art

It is often desirable to use multiple guidewires in various endovascularprocedures. For example when deploying stent graft aneurismal repairdevices within branched vasculature, a first guidewire would be used toaccess the main artery while second and/or third guidewires would accessthe side branched arteries. Stent grafts with multiple guidewire portswould then be advanced along the respective guidewires and deployed atthe desired sites. A common problem associated with the use of multipleguidewires is the “crossing” or entanglement of the guidewires in thevasculature proximal to the treatment site. Crossed and entangledguidewires prohibit or severely restrict the ability to advance a devicewith multiple guidewire ports to the treatment site. An introducercatheter or sheath is often employed to protect the vasculature frompossible damage due to the advancement of the guidewires, catheters andsubsequent devices but such use does not eliminate the occurrence ofcrossed guidewires. See for example U.S. Pat. No. 6,884,258 (to Vardi etal.) for a disclosure of problematic crossed guidewires.

SUMMARY OF THE INVENTION

The invention comprises a conduit (such as an introducer sheath or aguide catheter) for use in an interventional procedure comprising: amain body having a length; at least one disruptable barrier within themain body extending along at least a portion of the length of the mainbody, defining at least two lumens within the main body; and wherein thebarrier is adapted to be disrupted before or during the procedure toreduce the number of lumens within the main body. In an aspect of theinvention the at least two lumens are adapted to receive separateelongated members (such as guide wires) and prevent the elongatedmembers from tangling with each other.

An aspect of the invention comprises an introducer sheath thatincorporates at least two separate lumens to prevent the entanglement ofat least two guidewires. The lumens are separated by disruptablebarrier(s) that allows multiple lumens to be converted into fewerlumens. The barrier(s) forms at least two separate lumens along at leasta portion of the length of the sheath. Guidewires and guide catheterscan be advanced through the separate lumens to a desired treatment site.The separated lumens prevent the guidewires from crossing and becomingentangled. In an aspect of the invention, an endovascular device havingmultiple guidewire lumens and ports can then be “back-loaded” onto theproximal ends of the guidewires. As the multi-lumen device is advancedthrough the introducer sheath, the distruptable barrier tears orseparates to form fewer lumens, thus allowing the multi-lumen device topass while maintaining guidewire separation. An operational procedureusing an introducer sheath of the present invention allows the user toinitially place all required guidewires into the target sites. After allrequired guidwires are in place, the interventional device or devicescan then be advanced along the guidewires.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of the abdominal part of the aortaand its principal branches showing an introducer sheath and multipleguidewires of the current art.

FIG. 2A is a partial, mid-section perspective view of a multi-lumenintroducer sheath according to a preferred embodiment of the presentinvention.

FIG. 2B is an end view of the introducer sheath of FIG. 2A. Shown aretwo disruptable barriers that form three lumens within the introducersheath.

FIG. 3 is a partial perspective view of a distal portion of anintroducer sheath according to the present invention. Shown are threeguidewires positioned within the aorta and within the two renalarteries.

FIG. 4 is a perspective view of an introducer sheath according to thepresent invention. Shown are the proximal ends of three guidewiresprojecting from the proximal hub assembly.

FIG. 5 is a partial cross-sectional schematic view of a distal end of astent delivery system that is compatible with an introducer sheath ofthe present invention.

FIG. 6 shows a perspective view of an introducer sheath 44 of thepresent invention. Shown is the distal end of the stent delivery systembeing advanced toward the proximal hub assembly.

FIG. 7 is a partial cross-sectional view of an introducer sheath withtwo disruptable barriers. The barriers are shown being ripped, deformedor in other words “disrupted” to form a single lumen within theintroducer sheath.

FIG. 8 is a partial perspective view of an introducer sheath that hasbeen fully “converted” or “transformed” into a single lumen catheter bythe disruption of the two internal barriers.

FIG. 9 is a partial perspective view of a stent delivery system alongwith an introducer sheath according to the present invention. Shown isthe introducer sheath being partially withdrawn to fully expose theconstrained self-expanding stent portion of the delivery system.

FIG. 10 is a schematic representation of an aortic section with apartial perspective view of a stent delivery system. Shown is a first or“main body” stent after deployment.

FIG. 11 is a schematic representation of an aortic section with aperspective view of a deployed main body stent. Shown are two guidewireswithin the targeted renal arteries that pass through two side portswithin the wall of the deployed main body stent.

FIG. 12 is a schematic representation of an aortic section with aperspective view of a deployed main body stent. Shown is a firstside-branch stent delivery system being advanced over the firstguidewire 34.

FIG. 13 is a schematic representation of an aortic section with aperspective view of a deployed main body stent. Shown is a first sidebranch stent that has been deployed into the right renal artery.

FIG. 14A is a schematic representation of an aortic section with aperspective view of a deployed main body stent. Shown is a second sidebranch stent that has been deployed into the left renal artery.

FIG. 14B is a schematic representation of an aortic section with aperspective view of a deployed main body stent and two attachedside-branch stents. Also shown is a dashed profile of a bifurcatedintraluminal device engaged into the main body stent.

FIGS. 15A through 15C are top plane views of three hemostatic sealingdisks that incorporate pre-punctured guidewire insertion sites andpre-slit device insertion slots.

FIG. 16 is a side view of three sealing disks aligned and stacked toform a hemostatic sealing disk assembly.

FIG. 17A is an end view of a multi-lumen catheter having three lumensprior to expansion.

FIG. 17B is an end view of the catheter of 17A after expansion. Thethree lumen catheter of 17A has been converted into a single lumencatheter by the expansion.

FIGS. 18A through 18C depict catheters with interior barriers that canbe disrupted. Once disrupted the catheter is converted into a catheterwith a fewer number of lumens.

FIG. 19A is an end view of a catheter having two lumens that willtransform into a single lumen catheter when expanded.

FIG. 19B is an end view of a catheter having three lumens that willtransform into a single lumen catheter when expanded.

FIG. 20 is an end view of a catheter of the present invention. Shown isan end view of a catheter having four disruptable barriers that formthree lumens. The three lumens can be converted into a single lumen whenexpanded.

FIG. 21 is an end view of a catheter of the present invention. Shown isa catheter having two disruptable barriers that form three lumens. Eachbarrier can have a slit (or other longitudinal opening) that can releasethe guidewires as a delivery catheter is advanced distally throughcatheter.

FIG. 22 is an end cross-sectional view of an introducer sheathsurrounding a dilator that has two flat surfaces. The clearance spacebetween the introducer sheath and the dilator flat surfaces form twoguidewire lumens.

FIG. 23 is an end cross-sectional view of an introducer sheathsurrounding a dilator that has three guidewire grooves.

FIG. 24 is an end cross-sectional view of an introducer sheathsurrounding a dilator that has two guidewire grooves and a centrallumen.

FIG. 25 is an end cross-sectional view of an introducer sheathsurrounding a dilator that has a “cross-shaped” profile that forms fourlumens.

FIGS. 26 and 27 are cross-sectional end views of guidewire positioningcatheters surrounded by an introducer sheath. The guidewire positioningcatheter has three guidewire lumens each having a longitudinal slit oropening. The slit or opening allows the guidewires to be released as asubsequent delivery system is advanced through the introducer sheath.

DETAILED DESCRIPTION OF THE INVENTION

A better understanding of the present invention may be had withreference to the several figures.

Shown in FIG. 1 is a schematic representation of the abdominal part ofthe aorta and its principal branches. The abdominal aorta 20 ischaracterized by a right renal artery 22 and left renal artery 24. Thelarge terminal branches of the aorta are the right and left common iliacarteries 26 and 28. Each common iliac artery branches into internal 30and external 32 iliac arteries. An external iliac artery 32 becomes thefemoral artery below the inguinal ligament. Internal iliac artery 30 isalso known as the hypogastric artery. Additional vessels (e.g., secondlumbar, testicular, inferior mesenteric, middle sacral) have beenomitted for simplification. The infrarenal aorta is that portion of theaorta disposed between the renal arteries and the common iliac arteries.Throughout this application the term “distal” refers to the directionthat is furthest away from the clinician or access site and the term“proximal” refers to the direction that is closest to the clinician oraccess site.

A typical procedure entails gaining initial femoral artery accesspercutaneously or with a surgical access. A floppy guidewire is theninserted into the artery past the treatment site to ensure access ismaintained. An introducer sheath consisting of the outer sheath and aninner dilator is placed over the guidewire and into the vessel to thetreatment site or as far as it will go. The dilator serves to bothstiffen the sheath for pushability and to create a smooth transitionbetween the relatively sharp end of the sheath and the tissue. Thefloppy guidewire is switched out for the appropriate stiff guidewireusing the sheath to maintain arterial access. The dilator is thenremoved and the treatment device is then guided over the guidewire anddeployed.

As shown in FIG. 1, first, second and third guidewires 34, 36, 38 havebeen positioned within the main aorta 20 and within the two renalarteries 22, 24. The guidewires have been positioned with the aid of asingle lumen introducer sheath 40 according to the current art. Asdepicted in the cut away portion of the introducer sheath, the threeguidewires 34, 36, 38 are “crossed” 42 and entangled within theintroducer sheath. The crossed and entangled guidewires prohibit orseverely restrict the ability to advance devices, and particularlymulti-lumen devices, to the treatment site.

FIG. 2A is a partial, mid-section perspective view of a multi-lumenintroducer sheath according to an aspect of the present invention. Shownis an introducer sheath portion 44 having two distruptable barriers 46,48 that can extend through a substantial length (or the entire length)of the introducer sheath 44. The two disruptable barriers 46, 48 formfirst, second and third lumens 50, 52, 54 that can extend through asubstantial length (or the entire length) of the introducer sheath 44.Typical hemostatic valves, radiopaque markers and sheath distal tipdetails have been omitted for clarity.

Shown in FIG. 2B is an end view of the introducer sheath 44 of FIG. 2A.Shown are the two disruptable barriers 46, 48 that form three lumens 50,52, 54 within the introducer sheath 44.

FIGS. 3 through 14 depict an operational procedure used to repair anaortic aneurysm that includes the deployment of three stent grafts. Thefirst stent graft is deployed across the main body of the aorta adjacentto the two renal arteries. The second and third stent grafts are thenguided through “side branch” openings within the main stent graft andare then deployed within the renal arteries.

FIG. 3 is a schematic representation of the abdominal part of the aortaand its principal branches. Included is a partial perspective view of adistal portion of an introducer sheath 44 according to an aspect of thepresent invention. Shown are three guidewires 34, 36, 38 positionedwithin the aorta 20 and within the two renal arteries 22, 24. Theguidewires have been positioned with the aid of a three lumen introducersheath 44 according to an aspect of the present invention. Eachguidewire is contained within a separate lumen within the introducersheath. As depicted in the cut away portion of the introducer sheath,the three guidewires 34, 36, 38 are separated 56 and prevented frombeing “crossed” as a result of the three separate lumens.

FIG. 4 is a schematic representation of an aortic section with aperspective view of an introducer sheath 44 according to the presentinvention. Shown is an introducer sheath 44 with three separate lumens50, 52, 54. Three guidewires 34, 36, 38 are shown, each guidewire beingcontained within one of the three separate lumens. The three guidewiresare positioned distally into the main portion of the aorta and into tworenal arteries. The proximal ends of the three guidewires project fromthe proximal hub assembly 58. The proximal hub assembly contains ahemostatic valve assembly that minimizes or prevents back-bleeding whilealso allowing advancement of guidewires and subsequent devices.Additional hubs and connectors, for example flushing hubs, have beenomitted for clarity.

FIG. 5 is a partial cross-sectional schematic view of a distal end of astent delivery system 60 that is compatible with an introducer sheath ofthe present invention. Shown is a catheter 71, containing two guidewiretubes 67, 69 along with a central catheter shaft 61. The guidewire tubes67, 69 have guidewire lumens 62, 66. The central catheter shaft 61 has aguidewire lumen 64. All four components 61, 71, 67, 69 extend to theproximal hub (not shown).

A self expanding main body stent or stent graft (for simplicity, as usedherein it should be understood that “stent” shall mean both a stent or astent graft) 63 is shown compressed onto the central catheter shaft 61.The self expanding stent 63 is constrained in the compressed state by aflexible sheath 65. The sheath 65 can be activated by a pull line (notshown) releasing a series of “slip-knots” that allow the sheath to splitopen and release the self expanding stent. The two guidewire tubes 67,69 are passed through two side-branch openings in the stent 63 and alsopass through two openings within the flexible sheath 65. The openings inthe flexible sheath can be configured, for example, as slits propagatingto the seam line of the flexible sheath.

The three guidewires 34, 36, 38 (from FIG. 4, emanating from theproximal hub assembly 58) are shown being “back-loaded” into the threeguidewire lumens 62, 64, 66 within the stent delivery system 60, in thedirection depicted by the arrows 73.

FIG. 6 shows a perspective view of an introducer sheath 44 of thepresent invention. Two guidewires 34, 38 are shown back-loaded into thestent delivery system tubes 67, 69. The third guidewire 36 is shownback-loaded into the guidewire lumen within the central catheter shaft61. Shown is the distal end of the stent delivery system 60 beingadvanced in the direction 68 toward the proximal hub assembly 58.

Shown in FIG. 7 is a partial cross-sectional view of an introducersheath 44 according to the present invention. A distal end of a stentdelivery system 60 has been inserted through the proximal hub assembly58 (see FIG. 6) and is being advanced distally in the direction depictedby arrow 68. In portion 72, the three guidewires 34, 36 and 38 areseparated by the disruptable barriers 46 and 48. As the stent deliverysystem 60 is advanced, the barriers 46 and 48 tear, rip, deform or inother words “disrupt” 70, thereby forming a single lumen within theintroducer sheath portion 74.

The term “disruptable barrier” is defined as a member that creates atleast two lumens within a catheter shaft and is tailored to allowconversion to a fewer number of lumens. For example a pair ofdisruptable barriers can create three separate lumens that are thentransformed into less than three lumens. Similarly, flexible partitionsor walls within a catheter can initially form several lumens (forexample four) that are subsequently converted into less than fourlumens. A disruptable barrier (or barriers) therefore provides a meansto prevent entanglement of at least two guidewires, while also allowingthe subsequent advancement of a medical device along the guidewires. Inan aspect of the invention, a disruptable barrier (or barriers) providesa means to isolate and prevent entanglement of at least two guidewires,while also allowing the subsequent advancement of a medical device alongthe guidewires.

FIG. 8 is a schematic representation of an aortic section with a partialperspective view of an introducer sheath 44 according to the presentinvention. Shown is the distal end of a stent delivery system 60projecting from the distal end of the introducer sheath 44. Theintroducer sheath 44 has been fully “converted” or “transformed” into asingle lumen catheter by the disruption of the two internal barriers(46, 48 FIG. 2A). Also shown are three guidewires 34, 36 and 38 locatedwithin the aorta and within two renal arteries. The three guidewires arecontained within the stent delivery system guidewire lumens (62, 64 and66 of FIG. 5).

FIG. 9 is a schematic representation of an aortic section with a partialperspective view of a stent delivery system 60 along with an introducersheath 44 according to the present invention. Shown is the introducersheath 44 being partially withdrawn from the distal end of the stentdelivery system 60, in the direction depicted by arrow 76. The sheath 44is partially withdrawn to fully expose the constrained self-expandingstent portion of the delivery system 60.

FIG. 10 is a schematic representation of an aortic section with apartial perspective view of a stent delivery system. Shown is a first or“main body” stent 78 after deployment. In a preferred embodiment themain body stent is self-expanding and has appropriate side hole openings80 and 82 that roughly align to the side branch arteries to besubsequently stented. The main body stent 78 is compacted into the stentdelivery system 60 (FIG. 9) with the two guidewire tubes 67, 69 and twoside branch guidewires 34, 38 pre-routed through the appropriate sideholes or ports in the main body stent. Thus when deployed, the two sidebranch guidewires 34, 38 remain within the target vessels and arepre-routed through the side ports in the main body stent. The flexiblesheath (FIG. 5, item 65) has been omitted for clarity.

FIG. 11 is a schematic representation of an aortic section with aperspective view of a deployed main body stent 78. Shown are twoguidewires 34, 38 within the targeted renal arteries that pass throughtwo side ports 80, 82 within the wall of the deployed main body stent78. Shown is the central shaft 61 of the stent delivery system (60, FIG.9) being withdrawn along with the two guidewire tubes 67, 69 and thecatheter shaft 71, in the direction depicted by arrow 76. The threeguidewires 34, 36, 38 remain in their target vessels.

Shown in FIG. 12 is a schematic representation of an aortic section witha perspective view of a deployed main body stent 78. Shown is a firstside-branch stent delivery system 86 being advanced over the firstguidewire 34, in the direction indicated by arrow 68. The side-branchstent can be self expanding and constrained by a sheath in a mannersimilar to that of the main body stent of FIG. 5.

Shown in FIG. 13 is a schematic representation of an aortic section witha perspective view of a deployed main body stent 78. Shown is a firstside branch stent 88 that has been deployed into the right renal artery22. The first side branch stent 88 has been deployed through the firstside branch port 80 creating a seal between the main body stent 78 andthe first side branch stent 88.

Shown in FIG. 14A is a schematic representation of an aortic sectionwith a perspective view of a deployed main body stent 78. Shown is asecond side branch stent 90 that has been deployed into the left renalartery 24. The second side branch stent 90 has been deployed through thesecond side branch port 82 creating a seal between the main body stent78 and the second side branch stent 90.

The existing guidewire placements can be subsequently used foradditional diagnostics or repairs (such as ballooning or stentplacement). Additional repair or diagnostic devices can include but arenot limited to bifurcated stent grafts, single lumen tube grafts,combinations of modular graft components, radiographic injectiondevices, embolic filters, occlusion, anchoring or seating balloons,fixation or anchoring devices and endoscopes. In a preferred example thetwo side-branch guidewires 34, 38 can be withdrawn and an additionaldevice (or devices) can be advanced along the central guidewire 36. Whenat the desired location subsequent devices can be released and engagedto the “docking” portion 92 of the main body stent 78 forming a completerepair of the aneurysmal site.

For example, shown in FIG. 14B is a schematic representation of anaortic section with a perspective view of a deployed main body stent 78and two attached side-branch stents. Also shown is a dashed profile of abifurcated intraluminal device 94 engaged into the docking portion 92 ofthe main body stent 78.

As shown in FIG. 14A, the stents 78, 88, 90 can be balloon expandable,self expanding or both. Self expanding stents can be further “seated”with a balloon if desired, using the appropriate guidewire orguidewires. The side ports 80 and 82 in the main body stent 78 canincorporate side branch stent sealing features such as conicalinterfaces, support frames, compliant surfaces etc. that enhance ormaintain an effective seal between the stents. Side branch stents 88 and90 can similarly incorporate sealing features.

Although depicted in a renal/aortic repair procedure, the devices andmethods of the present invention can be used in other repair proceduresinvolving branched vessels. Anchoring balloons can also be incorporatedinto the various guidewires to help maintain the guidewire positionsduring the repair procedure.

During the insertion of an introducer sheath of the present invention a“split” dilator can be used in a normal fashion. Such a split dilatorhas longitudinal slits or separate stiffening portions that are tailoredto slip into the individual lumens of the introducer sheath of thepresent invention.

The disruption or tearing of the barrier or barriers of the presentinvention can be initiated, for example, with the use of a “slittingtool”. Such a slitting tool can be partially inserted into theintroducer sheath of the present invention prior to the back loading ofthe first stent device. The slitting tool can initiate the disruption orseparation of the barrier/s and can then be removed prior to the deviceinsertion. Similarly, the distal tip of the first stent device canincorporate a barrier “disrupting” feature such as a sharp or flutedsurface. Also, the barrier can be of a material that will tear as arelatively blunt distal tip of a catheter is advanced.

When multiple guidewires are used with an introducer sheath, aneffective hemostatic seal within the proximal hub assembly (FIG. 6, item58) is desirable to minimize back-bleeding. Elastomeric sealing diskscan be incorporated into a proximal hub assembly (FIG. 6, item 58) thatare configured to allow the insertion of multiple guidewires followed bythe insertion of a larger device or delivery system. Shown in FIG. 15Athrough 15C are top plane views of three sealing disks 100A, 100B, 100Cthat incorporate pre-punctured guidewire insertion sites 102. Theguidewire insertion sites can be interconnected to allow for theformation of one orifice for the subsequent advancement of a largerdevice or delivery system. For example, shown are pre-puncturedguidewire insertion sites 102 interconnected by linear pre-slit deviceinsertion features 104, or interconnected by curved pre-slit deviceinsertion features 106. The seals can also incorporate “rip able”sections that readily separate or tear as an alternative to pre-slitinsertion features. Multiple sealing disks can then be aligned andstacked together within the hub assembly to form an effective guidewireor device hemostatic seal. Shown in FIG. 16 is a side view of threesealing disks 100A, 100B, 100C aligned and stacked to form a sealingdisk assembly 108.

Disruptable barriers of the present invention can have variousconfigurations. Shown for example in FIG. 17A is an end view of amulti-lumen catheter 110A having first, second and third lumens 112,114, 116. The multi-lumen catheter 110A can be expanded (for example bythe insertion of a device delivery system) to form a single lumen 118within the catheter as shown in end view, FIG. 17B. Thus the barriers ofFIG. 17A “disrupt” to form a catheter with fewer lumens. Suitablematerials for use as disruptable barriers include, but are not limitedto, polyethylene, polypropylene, polyvinyl chloride, polyurethanes,siloxanes, polyetherester, polytetrafluoroethylene, polyimide, nylon,polyethylene terephthalate, thermoplastic elastomers, polyolefins,polyester, polyamides, polydimethylsiloxane, natural rubber, polyetherblock amide (PEBAX), ethylene vinyl acetate, and combinations thereof.

Similarly, FIGS. 18A through 18C depict catheters with interior barriersthat can be disrupted to form fewer lumens. Shown in FIG. 18A is an endview of a catheter 120A with two disruptable barriers 122 that formfirst and second lumens 112, 114. Shown in FIG. 18B is an end view of acatheter 120B with three disruptable barriers 122 that form first,second and third lumens 112, 114, 116. Shown in FIG. 18C is an end viewof a catheter 120C with four disruptable barriers 122 that form first,second, third and fourth lumens 112, 114, 116, 117. In these embodimentsthe barriers can be disrupted by pushing a device (or devices) distallyalong guide wire(s) previously located in the lumens. The barriers canbe disrupted by being pushed aside as the device is advanced along theguide wire.

Other configurations of the present invention, similar to that of FIG.17A, are configured with disruptable barriers. Shown for example in FIG.19A is an end view of a catheter 124A having two lumens 112, 114 thatwill transform into a single lumen catheter when expanded. Shown in FIG.19B is an end view of a catheter 124B having three lumens 112, 114, 116that will transform into a single lumen catheter when expanded.

Shown in FIG. 20 is an end view of a further embodiment of the presentinvention. Shown is an end view of a catheter 126 having fourdisruptable membranes 122 that form three lumens 112, 114, 116. Thethree lumens can be converted into a single lumen when expanded. Or, asdiscussed above, the lumens can be converted into a single lumen bybeing pushed aside by a suitable device (or devices) as the device(s) isadvanced along guidewire(s) previously located in the lumens.

Shown in FIG. 21 is an end view of an alternate embodiment of thepresent invention. Shown is an end view of a catheter 130 having twodisruptable barriers 131 that form three lumens 112, 114, 116.Guidewires are advanced and retained in these flexible cylindricallumens internally tangent to the inner surface of the catheter. Eachbarrier can have a slit (or other longitudinal opening) that can releasethe guidewires as a delivery catheter is advanced distally throughcatheter 130.

Various cross-sectional profiles according to the present invention canbe extruded, formed by wrapping or windings, or be comprised of multiplesections laminated or bonded together. The initial number of lumens caninclude but are not limited to two, three, four, five, six, seven,eight, nine or ten or more lumens. These multi-lumen catheters can beconverted, according to the present invention, into “fewer than theinitial number of lumens” which includes but is not limited to one, two,three, four, five, six, seven, eight, nine or ten or more lumens.

A catheter or introducer sheath having two disruptable barriers that are“rip able”, “slit able” or tear able can be fabricated by providing, forexample, a three piece mandrel having a general cross-section or endview according to FIG. 2B. A tubular member that has relatively highlongitudinal strength but with relatively low radial strength can beplaced around the center section of the three piece mandrel, forming anassembly. The assembly can then be wrapped with an adhesive coated filmor constrained by an adhesive coated tube. After adhesive curing, themandrel sections can be removed producing a catheter having the generalcross-sectional profile as shown in FIGS. 2A and 2B. The outer wall ofthe catheter is therefore formed by the film wrap or tubular constraint.The two disruptable, (e.g., “rip able”, “slit able”, or tear able)barriers are formed from the tubular member. The low radial strength ofthe tubular member allows for the tubular member to be readily slitalong its longitudinal axis. Suitable materials for use as rip able,slit able, or tear able barriers include, but are not limited to,polyethylene, polypropylene, polyvinyl chloride, polyurethane,siloxanes, polyetherester, polytetrafluoroethylene, polyimide, nylon,polyethylene terephthalate, thermoplastic elastomers, polyolefins,polyester, polyamides, polydimethylsiloxane, natural rubber, polyetherblock amide (PEBAX), and ethylene vinyl acetate, and combinationsthereof.

As an alternative to the concept of “disruptable barriers” modified“dilators” used in conjunction with introducer sheaths can be used tominimize or prevent the occurrence of crossed or entangled guidewires.The dilator has a length, a proximal end, and a distal end, the dilatoris sized to be locatable within the lumen of an introducer sheath. Theintroducer sheath has a length, a proximal end, a distal end, and alumen extending from the proximal end to the distal end. The dilator isfurther defined as having an outer geometric shape that defines at leasttwo lumens between the introducer sheath and the dilator when thedilator is inserted into the introducer sheath lumen. Moreover, thedilator can comprise at least one lumen defined by an inner surface ofthe dilator.

For example, a dilator can have two opposing flat surfaces extendingalong its length. When inserted into the mating introducer sheath, theflat surfaces form two guidewire lumens between the dilator and theinner wall of the introducer sheath. When the guidewires are positionedinto the desired target site the dilator can be removed and a deliverysystem can then be back-loaded onto the guidewires and advanced throughthe introducer sheath. The proximal guidewire positions can bemaintained by suitable fixation at the hub assembly. Shown in FIG. 22 isan end cross-sectional view of an introducer sheath 132 surrounding adilator 134 that has two flat surfaces 136. The clearance space betweenthe introducer sheath 132 and the dilator flat surfaces 136 form twoguidewire lumens. Shown are two guidewires 138 positioned within theclearance space between the introducer sheath 132 and the dilator flatsurfaces 136. Clearances between the introducer sheath 132 and dilator134 have been exaggerated for clarity.

Shown in FIG. 23 is an alternate dilator according to the presentinvention. Shown is an end cross-sectional view of an introducer sheath132 surrounding a dilator 134 that has three guidewire grooves 140.Similarly, shown in FIG. 24 is an end cross-sectional view of anintroducer sheath 132 surrounding a dilator 134 that has two guidewiregrooves 140 and a central lumen 142, formed by the inner surface of thedilator.

Shown in FIG. 25 is an alternate dilator according to the presentinvention. Shown is an end cross-sectional view of an introducer sheath132 surrounding a dilator 134 that has a “cross-shaped” profile 144 thatforms four lumens.

The modified dilators of the present invention therefore provide a“means to isolate and prevent entanglement of at least two guidewires”while also allowing the subsequent advancement of a medical device alongthe guidewires.

The specific configurations used to form separate guidewire lumens inthe examples above can be embodied along the entire length of thedilator. Alternatively, the guidewire lumen features can be eliminatedat the distal and/or proximal ends of the dilator. The elimination ofthe guidewire features for example at the distal end of the dilatorallows a normal tapered tip of a dilator to extend from the introducersheath during insertion. The dilator can then be further advanced intothe introducer sheath to expose the distal guidewire lumens. Thespecific lumens of the present invention can be dimensioned to accept avariety of guidewire sizes or other devices. In any event, once theguidewires are advanced through the lumens and located at the desiredtreatment sites, the dilator can be removed from the introducer sheathlumen to allow for the advancement of the desired device(s) over theguidewires. The concepts of disruptable barriers can be combined withdilators modified to incorporate guidewire lumens. In addition thedistal end of an introducer sheath can have staggered and/or angulatedexit ports for the guidewires or other devices.

Shown in FIGS. 26 and 27 are cross-sectional end views of guidewirepositioning catheters 146A-B surrounded by an introducer sheath 132. Asshown in FIGS. 26 and 27, the guidewire positioning catheter 146A-B hasthree guidewire lumens 112, 114, 116 each having a longitudinal slit oropening. The slit or opening allows the guidewires to be released as asubsequent delivery system is advanced through the introducer sheath.

The guidewire positioning catheters of the present invention thereforeprovide a means to isolate and prevent entanglement of at least twoguidewires while also allowing the subsequent advancement of a medicaldevice along the guidewires.

A method of the present invention can include the following steps:

-   A) provide an introducer sheath and a matching dilator system that    provides a means to prevent entanglement of at least two guidewires;-   B) insert and locate the introducer sheath approximate to a desired    target site;-   C) insert and locate at least two guidewires within the introducer    sheath;-   D) back-load a medical device onto the at least two guidewires; and-   E) advance the medical device over the at least two guidewires    through the introducer sheath to the desired target site.

The means to prevent entanglement of at least two guidewires can includethe incorporation of at least one disruptable barrier within theintroducer sheath. Additional means to prevent entanglement of at leasttwo guidewires can include, but are not limited to, the incorporation ofat least two guidewire lumens into the dilator or by the use of aguidewire positioning catheter.

While particular embodiments of the present invention have beenillustrated and described above, the present invention should not belimited to such particular illustrations and descriptions. It should beapparent that changes and modifications may be incorporated and embodiedas part of the present invention within the scope of the followingclaims.

1. A conduit for use in an interventional procedure comprising: a mainbody having a length; at least one disruptable barrier within the mainbody extending along at least a portion of the length of the main body,defining at least two lumens within the main body; wherein the barrieris adapted to be disrupted before or during the procedure to reduce thenumber of lumens within the main body.
 2. The conduit of claim 1,wherein the lumens are each adapted to receive a separate elongatedmember and prevent the elongated members from tangling with each other.3. The conduit of claim 2, wherein at least one of the elongated membersis used to access side vessels.
 4. The conduit of claim 1, thatcomprises at least two disruptable barriers, defining at least threelumens within the main body.
 5. The conduit of claim 1, that allows fordelivery of a main treatment device through the main body followingdisruption of the barrier.
 6. The conduit of claim 1, that includes atleast one hemostatic seal having multiple openings, each correspondingwith each of the lumens in the main body.
 7. The conduit of claim 6,wherein the multiple openings are adapted to form into a single opening.8. The conduit of claim 1, wherein the barrier comprises a membrane. 9.The conduit of claim 2, wherein the elongated member is a guidewire. 10.The conduit of claim 1, wherein the disruptable barrier materialcomprises a material selected from the group consisting of polyethylene,polypropylene, polyvinyl chloride, polyurethanes, siloxanes,polyetherester, polytetrafluoroethylene, polyimide, nylon, polyethyleneterephthalate, thermoplastic elastomers, polyolefins, polyester,polyamides, polydimethylsiloxane, natural rubber, polyether block amide,ethylene vinyl acetate, and combinations thereof.
 11. The conduit ofclaim 1, wherein the conduit is an introducer sheath.
 12. The conduit ofclaim 1, wherein the conduit is a guide catheter.
 13. The conduit ofclaim 1, wherein the at least one disruptable barrier extends forsubstantially the entire length of the conduit.
 14. An introducer sheathhaving a length, a proximal end, and a distal end comprising: Ahemostatic seal located at the proximal end; The hemostatic sealcomprising at least one elastomeric sealing disk; The at least oneelastomeric sealing disk comprising a plurality of interconnectedguidewire insertion sites.
 15. The introducer sheath of claim 14,wherein the hemostatic seal comprises at least three elastomeric sealingdisks.
 16. The introducer sheath of claim 14, wherein the at least oneelastomeric sealing disk comprises at least three guidewire insertionsites.
 17. The introducer sheath of claim 15, wherein the at least oneelastomeric sealing disk comprises at least three guidewire insertionsites.
 18. The introducer sheath of claim 14, wherein the plurality ofguidewire insertion sites comprise pre-punctured holes sized to accept aguidewire therethrough.
 19. A kit comprising: An introducer sheathhaving a length, a proximal end, a distal end, and a lumen extendingfrom the proximal end to the distal end; and A dilator having a length,a proximal end, and a distal end, the dilator being sized to belocatable within the lumen of the introducer sheath and having an outergeometric shape that defines at least two lumens between the introducersheath and the dilator when the dilator is inserted into the introducersheath lumen.
 20. The kit of claim 19, wherein the dilator outergeometric shape comprises at least two longitudinally extending groovessized to accept a guidewire.
 21. The kit of claim 19, wherein thedilator outer geometric shape is cross-shaped, the cross-shape formingfour lumens between the dilator and the introducer sheath when thedilator is inserted into the introducer sheath lumen.
 22. The introducersheath of claim 14, wherein the guidewire insertion sites areinterconnected by at least one slit.
 23. The conduit of claim 1, whereinthe main body has a first outer diameter, wherein the first outerdiameter is expandable to a relatively larger diameter upon insertion ofat least one elongated member into the main body.